Earth-boring tools are used to form wellbores in subterranean formations and include, for example, rotary drill bits (e.g., rolling cutter drill bits, fixed-cutter drag bits, bi-center bits, eccentric bits, and coring bits), percussion drill bits, reamers (including underreamers), and mills.
An earth-boring rotary drill bit 100 is shown in FIG. 1 that includes a bit body 102. The bit body 102 may be predominantly comprised of a particle-matrix composite material or a metal alloy such as steel. As shown in FIG. 1, the bit body 102 may be secured to a shank 104 having a threaded connection portion 106 (which may conform to industry standards such as those promulgated by the American Petroleum Institute (API)) for attaching the drill bit 100 to a drill string (not shown). The bit body 102 may be secured to the shank 104 using a blank or an extension 108, which also may be predominantly comprised of a metal alloy such as steel, although the bit body 102 optionally may be secured directly to the shank 104.
The bit body 102 shown in FIG. 1 includes internal fluid passageways (not shown) that extend between the face 103 of the bit body 102 and a longitudinal bore or plenum (not shown), which extends through the shank 104, the extension 108, and partially through the bit body 102. Nozzle inserts 124 are provided at the face 103 of the bit body 102 within the internal fluid passageways. The bit body 102 includes a plurality of blades 116 that are separated by junk slots 118. Gage pads 122 and wear knots 128 are also provided on the bit body 102. A plurality of cutting elements 110 (which may include, for example, PDC cutting elements) are attached to the face of the bit body 102 in cutting element pockets 112 that are located along each of the blades 116. The cutting elements 110 may be generally cylindrical, and may have a front cutting face 114 and a generally cylindrical lateral side surface 115.
When fabricating an earth-boring tool, such as the rotary drill bit 100 shown in FIG. 1, for example, the cutting elements 110 are secured to the body of the earth-boring tool by manually brazing each cutting element 110 into a cutting element pocket 112 previously formed in the body of the earth-boring tool. For example, a cutting element 110 is manually inserted into a cutting element pocket 112, after which a torch (not shown) may be used to heat the cutting element 110 and the body of the tool adjacent the cutting element pocket 112. After heating the cutting element 110 and the body to an elevated temperature (e.g., about 500° C.-700° C.), the torch may be used to manually heat and melt a metal or metal alloy brazing material, and the molten brazing material may be manually applied to the interface between the cutting element 110 and the surfaces of the body defining the cutting element pocket 112 therein. As the molten brazing material is applied to the interface between the cutting element 110 and the surfaces of the body defining the cutting element pocket 112, the cutting element 110 may be rotated or spun within the cutting element pocket 112 in an effort to at least substantially fill the gap or gaps between the cutting element 110 and the surfaces of the body defining the cutting element pocket 112 at the interface therebetween.
Such manual processes are often conducted by two persons, one of which operates the torch and applies the molten brazing material to the interface between the cutting element 110 and the surfaces of the body defining the cutting element pocket 112, and the other of which rotates the cutting element 110 within the cutting element pocket 112 as the molten brazing material is applied to the interface between the cutting element 110 and the surfaces of the body defining the cutting element pocket 112.